Table VI. Non-Hydrogen Atomic Coordinates for 2c with Esd's in Parentheses y_z_B^, A2 Pt 0.23633 (4) 0.81275 (3) 0.171561 (20) 1.955 ( PI 0.3093 (3) 0.64987 (20) 0.20193 (13) 2.22 (1 P2 0.1980 (3) 0.76938 (19) 0.05211 (13) 1.93 (1 Cll 0.1430 (3) 0.98185 (20) 0.13735 (14) 3.74 (l• C12 0.2677 (4) 0.85678 (23) 0.29793 (14) 4.52 (1 Cl 0.3006 (10) 0.5791 (7) 0.1137 (4) L9 (4) C2 0.3570 (12) 0.4794 (8) 0.1127 (5) 2.9 (5) C3 0.3593 (12) 0.4323 (8) 0.0485 (5) 3.3 (6) C4 0.2986 (12) 0.4828 (8) -0.0194 (5) 3.3 (5) C5 0.2432 (11) 0.5819 (7) -0.0200 (5) 17 (5) C6 0.2462 (10) 0.6328 (7) 0.0479 (4) 1.9 (4) Cll 0.5006 (11) 0.6271 (7) 0.2583 (5) 2.7 (4) C12 0.5253 (13) 0.6568 (9) 0.3406 (5) 4.1 (6) C13 0.6126 (12) 0.6795 (10) 0.2239 (6) 4.7 (6) C14 0.1866 (11) 0.5835 (8) 0.2495 (5) 2.8 (5) C15 0.2235 (14) 0.4687 (9) 0.2670 (6) 4.7 (7) C16 0.0279 (13) 0.5950 (10) 0.2082 (7) 5.5 (7) C21 0.3156 (11) 0.8302 (7) -0.0006 (5) 2.5 (5) C22 0.2753 (13) 0.9441 (8) -0.0215 (6) 4.3 (6) C23 0.4767 (12) 0.8188 (9) 0.0415 (5) 4.1 (6) C24 0.0070 (12) 0.7950 (8) -0.0032 (5) 3.2(5) C25 -0.1047 (12) 0.7665 (9) 0.0390 (6) 4.7 (6) C26 -0.0320 (13) 0.7488 (9) -0.0824 (6) 4.5 (6)done with a Broker built-in panic program. The J values are according to the data in Table I, and LW = 1.6 Hz. All NMR data are summarized in Table I.All of the reactions, manipulations, and purification steps involving phosphines were performed under a dry nitrogen or argon atmosphere.Other chemicals and solvents from commercial sources were used without further purification, except as noted.Syntheses. o-Phenylenebis(diisopropylphosphine) (l)2c and dichloro-[o-phenylenebis(diisopropylphosphine)]nickel(II) (2a) were prepared according to the literature methods.3dDichloro(o-phenylenebis(diisopropylphosphine)]paUadium(II) (2b). A mixture of DH (0.0723 mmol) and (PhCN)2PdCl2 (0.0723 mmol) in degassed dichloromethane (4 mL) was stirred at room temperature for 5 h, during which the solution became brown. Methanol (3 mL) was added to the reaction mixture, and the resulting solution was allowed to sit overnight. A colorless crystalline solid was collected (27.6 mg, 78%; mp 275 °C dec). Anal, Caled for Cl8H32P2Cl2Pd; C, 44.33; , 6.61.Found: C, 44.35; , 7.00.Dichloro[o-phenylenebis(diisopropylphosphine)]platinum(II) (2c). A flask was charged with DH (0.59 mmol) and K2PtCl4 (0.59 mmol), followed by a mixture of degassed water (5 mL) and ethanol (5 mL). The resulting suspension was stirred for 3 h, after which white precipitates were collected by filtration. The filtrate was extracted with CH2C12 to recover the remaining product, and the combined product was recrystallized from CH2Cl2/methanol. A colorless crystalline solid was obtained (195.2 mg, 57%; mp 280-285 °C dec). Anal. Caled for
Two dinuclear iron(II1) derivatives of Fe2L(OCH3)2C12 and Fe2LC14 stoichiometries, where L2-is the anion of the novel hexadentate Schiff base 1,4-piperazinebis(N-ethylenesalicylaldimine), have been obtained. The crystal structure of the methoxy complex has been determined by X-ray methods. The compound crystallizes in the monoclinic s ace group P2Jn(2)O. Least-squares refinement of 1727 observed reflections and 282 parameters has led to a final R factor of 0.087. The asymmetric unit is formed by two independent but quite similar dinuclear molecules. Each complex consists of two iron(II1) ions that are symmetrically bridged by two methoxy groups. The geometry around the iron atoms is roughly octahedral.Three coordination sites are occupied by one oxygen and two nitrogens (cis) of hexadentate Lz-and the remaining three by the two bridging methoxy groups and a terminal chlorine atom. The average Fe-O(bridging) bond length is 1.99 A, the mean Fe-Fe separation is 3.106 A, and the FeOFe angle averages 103'. The magnetic susceptibilities of powdered samples of Fe2L(OCH3)2C12 and Fe2LC14 have been examined in the temperature ranges 7-289 and 9C-300 K, respectively. The methoxy compound exhibits an antiferromagnetic exchange interaction with the best fit to the Van Vleck equation yielding J = -16.3 cm-l, with g = 2.00 and TIP = 0. The effective magnetic moment of Fe2LC14 is essentially temperature independent, 5.8 k 0.2 wB, and closely corresponds to the spin-only value (5.9 pB) expected for an exchange-noninteracting high-spin system. A comparison of the magnetic and structural properties of Fe2L(OCH3),C1, to those of the other X-ray structurally determined iron(II1) compounds containing Fe-0-Fe-0 rings does not indicate any correlation between J and the bridging angle at oxygen or the electron density at the bridging atom. Infrared, ESR, and UV-vis spectral data for both Fe2L(OCH3)2C12 and Fe2LCI4 are reported. with eight formula units in a cell of dimensions a = 25.924 (3) A, b = 18.923 (3) A, c = 12.496 (3) w , and / 3 = 90.19
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